Delivery of Heavy Books

Hi all!
Is there anyone here who has experienced ordering books from an international seller and shipping it here in the Philippines? I want to order a boxed set of the Harry Potter books (the UK edition), and I am thinking that it's quite heavy and it might get taxed more than the usual books. Before, I ordered 1 hardback book from the UK and I only had to pay 40 pesos to the mailman who delivered it to me. I am not sure if this applies to many books as well, or if I will have to pay thousands of pesos to the post office or customs.
Thanks!

normally when you buy an item online, the seller includes the shipping cost which is computed on the consumed volume space of the box to fit all the books and handling fee which it doesnt compute the weight of the book. Only additional fee for fragile items. The books will be delivered in the city post office and you'll pay and small amount for the postal storage fee.

I am not sure how much it costs then.
I have my Harry Potter edition direct from UK ,as my mom's gift and it's heavy.
So, if you were to order the whole series, I am sure it's too heavy really.
Anyway, if you can afford to buy the whole series, I am sure you can pay the mailman as well...not too big compared to the whole amount of those books aint?
have a good day jaiho®